1. Field of the Invention
The present invention is directed to a control unit responsive to a fluid pressure and a method of providing control signals.
2. Prior Art
In the fluid handling art and in particular in systems such as a turbocharger system which supplies air at a pressure for an engine such as an airplane engine, the output of the turbocharger must be controlled in response to the required manifold pressure and preferably must be adjusted for the altitude of the aircraft and for the density of the gases being provided by the turbocharger. Present systems accomplish this by the pilot or airplane personnel manually making adjustments in response to indication sensed from various points in the turbocharger system to control the speed of the turbocharger. Automatic control systems have been proposed which include a series of sensing units measuring pressure at various points in the system against their respective reference unit with the output of each of the sensing units being interconnected to provide an ultimate summation of their signal to the control circuit. Such systems require extensive mechanical linkages between the various sensing units and extensive adjustments of the various reference units to obtain the desired control for the turbocharger systems.